Method for making food patty

ABSTRACT

A method and apparatus are disclosed for forming a relatively porous patty of plastic food material that is subject to shrinkage during cooking. One embodiment of the apparatus includes a foraminous member having a plurality of apertures and a piston slidably disposed in a receiving chamber on one side of the foraminous member. A pressurizable feed chamber is provided with a feed mechanism for feeding and pressurizing the food material and forcing the material through the apertures and into the receiving chamber. A mold is provided for being aligned with the foraminous member and for receiving the material as it is discharged from the receiving chamber by movement of the piston. The discharging material impinges upon a wall of the mold to form a patty in which the material defines interstitial voids therein for entrapping air and providing retention of cooking juices to promote more rapid and uniform cooking of the patty.

DESCRIPTION Technical Field

This invention relates to a type of patty made from plastic foodmaterial, such as ground meat and the like, to a method for making sucha patty and to an apparatus for automatically making such a pattyaccording to the method of the invention. The method and apparatus ofthe invention are suited particularly form making patties of groundbeef, either alone or combined with desired additives.

Background Art

Patties of ground meat have been made for many years both by hand andautomatically by machine. Typically, such prior art patties have agenerally disc-like configuration. Since the ground beef patties arealso usually always intended for later cooking, it is desirable that thepatties have characteristics which permit them to be properly cooked toyield a cooked patty product having desirable appearance, texture, andtaste characteristics.

With some types of prior art patties, the density within the pattyvaries across the patty. Then, during cooking of such a variable densitypatty, the meat within the patty is not uniformly cooked. Thus, it wouldbe desirable to provide a patty having a generally uniform density tofacilitate more uniform cooking.

Many prior art patties are made by various types of automaticpatty-making apparatus which involve, at some stage in their operation,movement of a plate across one or more surfaces of the formed patty (oralternatively movement of the patty across a stationary surface).Frictional forces resulting from this movement tend to orient portionsof the surface of the patty in directions along the line of movement.

Some patties, especially patties of ground beef, contain tissue fiberswhich may be at first randomly distributed within the formed patty.However, frictional forces applied to the surface of the patty duringthe operation of the patty-making apparatus tend to unravel or stretchout the tissue fibers in the surface of the patty along the lines ofrelative movement and tend to orient the tissue fibers into a generallyparallel array across the surface or surfaces of the patty. A pattyformed with such parallel-oriented tissue fibers presents increasedresistance to biting or cutting across the patty in directions notparallel to the oriented surface tissue fibers. Thus, it would bedesirable to provide a patty in which the tissue fibers are randomlyoriented within the patty and to provide a method and apparatus formaking such a patty which tends to present the randomly oriented tissuefibers from becoming oriented in a particular direction on the surfacesof the patty.

It would be desirable to provide a patty in which the tissue fibers werenot oriented in a single direction for an additional reason related toshrinkage of the patty during cooking. Specifically, with long tissuefibers oriented in the patty in a generally single direction, the tissuefibers, upon being heated during cooking, tend to shrink along theirlength. If the tissue fibers are oriented generally in one direction,the patty dimension transverse to the tissue fiber orientation shrinkssubstantially less. Consequently, the cooked patty will have an ovalshape which may be aesthetically unattractive and which obviously doesnot conform to the typical circular hamburger-type bun.

Conventional methods of forming patties of food material rely upon theapplication of pressure to the material to create a relatively densepatty. It would be beneficial to provide a method for producing a pattyhaving a relatively high degree of porosity--a patty that would thencook more rapidly into a lighter and more juicy product. Further, itwould be advantageous if such a method could be used with apparatus insuch a way so as to avoid "plugging up" of the patty forming apparatuswith food pieces during operation.

SUMMARY OF THE INVENTION

The patty of the present invention comprises a plastic food material,such as ground meat and the like which is subject to shrinkage duringcooking. The food material is formed into a patty having a relativelyhigh degree of porosity. In one embodiment of the patty, the foodmaterial is formed into a plurality of plugs which are packed togetherin an array which encloses air in the interstitial regions. Thisstructure promotes more rapid and uniform cooking of the patty and aidsin retention of the cooking juices.

According to the method of the present invention, the plastic foodmaterial is discharged from a plurality of cavities defined in aforaminous member or through a formaminous plate into a mold to form apatty of relatively high porosity. In one form of the method, theplastic food material is first formed into a plurality of plugs and theplugs are then assembled into a closely packed, but porous array.

More specifically, the patty may be made by feeding a quantity ofplastic material in a first direction under pressure through aperturesin a plate or into or through a plurality of elongate pressurizable plugforming cavities through the open end of each cavity. After apredetermined amount of material has been so fed, the feeding of thematerial is terminated. Next the material is discharged or extruded, ina second direction, through or out of the apertures or cavities into asuitable mold.

The bidirectional movement of food material provides an effectiveself-cleaning action which prevents the cavities from being plugged upby the food material. Specifically, some food material, such as groundbeef, contains string-like tissue fibers. During the movement of thefood material into the cavities, it is possible that a single tissuefiber may be forced into two or more cavities and then may "hang up"across the cavity openings. Tissue fibers that get caught or hung upduring the movement of the food material in one direction are dislodgedfrom the cavities during the subsequent movement in the oppositedirection. The continued periodic bidirectional movement of foodmaterial into and out of the cavities thus continuously removes any"plugging" material.

In an embodiment where the food material is extruded as plugs throughplug forming cavities, the mold preferably includes an impingementsurface spaced from the open ends of the plug forming cavities so thatthe plugs of material discharging from the cavities are directed againstthe impingement surface. This causes the plugs of material tocircumferentially expand so that portions of each plug come into contactwith portions of adjacent plugs thereby flattening the walls of theplugs along the areas of contact. At the same time, interstitial voidsare necessarily formed between other portions of the plugs forentrapping air therein and for aiding in retention of cooking juices.

One embodiment of the novel apparatus for forming the unique patty ofthe present invention in accordance with the method of the presentinvention includes a hopper for holding a supply of plastic foodmaterial, a pressurizable feed chamber communicating with the hopper toreceive food material from the hopper, and a means for feeding thematerial from the hopper within the pressurizable feed chamber. Theapparatus further includes a multi-cylinder plug forming blockcontaining a plurality of plug forming cavities, with each plug formingcavity having an open end. A piston is slidably disposed within eachplug forming cavity and is adapted to move from a retracted loadingposition to an extended discharging position within the cavity.

A mold is provided for being aligned with the plug forming cavitiesafter they have been filled with the food material and for receiving thedischarging plugs of material as the pistons are moved to thedischarging position within plug forming cavities.

Preferably the mold has a cylindrical side wall and includes animpingement wall or surface opposite the plug forming cavities againstwhich the discharging plugs of material impinge to cause circumferentialexpansion of the plugs within the mold to form a circular patty ofexpanded plugs in a closely packed array within interstitial voidsdefined between adjacent plugs.

In another embodiment of the apparatus, the multi-cylinder plug formingblock is substantially reduced in thickness so that it, in effect,becomes a relatively thin plate with a plurality of apertures. Insteadof individual pistons in each aperture, a single piston is provided in areceiving chamber above the plate. Food material is first forced throughthe apertures in the plate and then into the receiving chamber.Subsequent movement of the piston toward the plate squeezes the foodmaterial back through the apertures as relatively thin extrusions whichtend to curl and which expand and join together to form a relativelyporous patty in the mold.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and embodiments thereof, from the claims and from theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings forming part of the specification, and inwhich like numerals are employed to designate like parts throughout thesame,

FIG. 1 is a perspective view of one embodiment of the apparatus of thepresent invention shown operably associated with a horizontal pattyconveyor, of which only a fragmentary portion is illustrated;

FIG. 2 is an enlarged, fragmentary, perspective view of part of theupper portion of the apparatus illustrated in FIG. 1 showing the moldingregion in more detail;

FIG. 3 is a view similar to FIG. 2 but with the molding mechanisms andcover plates removed to better illustrate the food material feed chamberand feed mechanisms;

FIG. 4 is a view similar to FIG. 3 but showing the food material beingpressurized by the feed mechanism and the closure plate actuator movedoutwardly by the pressurized food material;

FIG. 5 is an enlarged, fragmentary, cross-sectional view of the feedmechanism taken generally along the plane 5--5 in FIG. 4 and showingthree moved positions of the mechanism in dashed lines;

FIG. 6 is a view similar to FIG. 4 but with the cover plate and closuremember in place over the feed chamber;

FIG. 7, located on the sheet of drawings along with FIGS. 1 and 2, is agreatly enlarged, prespective, fragmentary view of the multiplepressurizing cylinder and piston assembly with a portion broken away tobetter illustrate the assembly;

FIG. 8 is a cross-sectional view taken generally along the plane 8--8 inFIG. 2 showing the multiple pressurizing cylinder/piston assembly beingfilled with food material;

FIG. 9 is an enlarged, fragmentary, cross-sectional view taken generallyalong the plane 9--9 in FIG. 8;

FIG. 10 is a fragmentary, cross-sectional view similar to FIG. 9 butshowing the mold transfer plate moved to the patty molding position;

FIG. 11 is a slightly reduced cross-sectional view taken along the plane11--11 in FIG. 10;

FIG. 12 is a fragmentary cross-sectional view similar to FIG. 10 butshowing the pressurizing pistons in the downwardmost positions andshowing a formed patty of food material in the mold cavity of thetransfer plate;

FIG. 13 is a greatly enlarged, fragmentary, cross-sectional view of thedistal end of one of the pressurizing pistons of the first embodiment ofthe apparatus of the present invention;

FIG. 14 is a fragmentary, cross-sectional view similar to FIG. 12 butshowing the transfer plate carrying a molded patty and moved to thepatty ejecting position;

FIG. 15 is a greatly enlarged, diagrammatic view of a portion of FIG. 12to show the plugs of food material as they are discharged from thepressurizing cylinders into the mold cavity;

FIG. 16 is a view similar to FIG. 15 but at a later point in time toshow the plugs of food material discharging from the pressurizingcylinders, expanding, and contacting adjacent plugs of food material;

FIG. 17 is a diagrammatic illustration of one embodiment of a patty offood material of the present invention formed in accordance with themethod of the present invention;

FIG. 18 is a greatly enlarged, fragmentary, perspective view of a smallportion of the patty illustrated in FIG. 17;

FIG. 19 is a diagrammatic illustration of the patty of food materialformed in accordance with the teachings of the prior art.

FIG. 20 is a fragmentary, diagrammatic illustration of a method offorming a patty of food material in accordance with the teachings of theprior art;

FIGS. 21 and 22 are diagrammatic illustrations of a patty formed inaccordance with the teachings of the prior art;

FIG. 23 is a fragmentary, diagrammatic illustration of a method ofextruding ground food material, such as in a meat grinder, as is wellknown in the prior art;

FIG. 24 is a fragmentary, diagrammatic, cross-sectional view of plugs ofground meat containing tissue fibers as the plugs are discharged fromthe plug forming cavities of the first embodiment of the apparatus ofthe present invention;

FIG. 25 is a fragmentary, cross-sectional view of a second embodiment ofthe apparatus of the present invention similar to FIG. 14 for the firstembodiment of the present invention;

FIG. 26 is a fragmentary, cross-sectional view taken generally along theplane 26--26 in FIG. 25;

FIG. 27 is a greatly enlarged, fragmentary, cross-sectional view takengenerally along the plane 27--27 in FIG. 25;

FIG. 28 is a greatly enlarged, fragmentary, cross-sectional view similarto FIG. 27 but diagrammatically illustrating the discharge of foodmaterial during molding of a patty;

FIG. 29 is a diagrammatic, perspective illustration of a type of pattyformed in accordance with the method of the present invention;

FIG. 30 is a diagrammatic, elevational view of the patty illustrated inFIG. 29;

FIG. 31 is a fragmentary, diagrammatic, perspective illustration ofanother type of patty formed in accordance with the method of thepresent invention;

FIG. 32 is a greatly enlarged, diagrammatic view of a modification ofthe second embodiment of the apparatus of the present invention, similarto FIG. 28, and diagrammatically illustrating the discharge of foodmaterial during molding of a patty; and

FIG. 33 is an enlarged, fragmentary, diagrammatic, perspectiveillustration of the type of patty formed in accordance with theapparatus and method illustrated in FIG. 32.

DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawings and will herein be described indetail preferred embodiments of the invention. It should be understood,however, that the present disclosure is to be considered as anexemplification of the principles of the invention and not intended tolimit the invention to the embodiments illustrated.

The precise shapes and sizes of the components herein described are notessential to the invention unless otherwise indicated, since theinvention is described with reference to an embodiment which is simpleand straightforward.

It will be understood that references made herein, and in the claims, tovarious terms such as "food material," "tissue," "fiber," and "cookingjuices," are used herein in a non-technical sense, and are intended toinclude various substances exhibiting the characteristics discussedhereinafter and to which this invention is directed.

For ease of description, the apparatus of this invention will bedescribed in a normal operating position and terms of upper, lower,horizontal, etc., will be used with references to its normal operatingposition. It will be understood, however, that the apparatus of thisinvention may be manufactured, stored, transported, and sold in anorientation other than the normal operating position described.

The apparatus of this invention has certain conventional drivemechanisms and control mechanisms the details of which, though not fullyillustrated or described, will be apparent to those having skill in theart and an understanding of the necessary functions of such mechanisms.

The apparatus of the present invention may be constructed of many typesof materials. The choice of material in some cases is dependent upon theparticular application involved and other variables, as those skilled inthe art will appreciate.

The molding apparatus of the illustrated embodiment of the apparatus 30of the present invention comprises a base 32 on which is supported anupstanding frame or enclosure 34 which, among other things, supports andencloses various drive mechanisms and controls for operating theapparatus that will be explained in more detail hereinafter. Mounted tothe top of the enclosure 34 is a hopper 36 which comprises a supplymeans for moldable plastic material or food material 38, such as groundmeat and the like.

The apparatus forms a novel patty of food material, such as finishedpatties 40 shown being carried away from the apparatus 30 on a endlessbelt conveyor 42. The conveyor 42 may be of any suitable design and isnot a part of the apparatus of the present invention. Typically,however, the conveyor 42 has means, not illustrated, associated with itfor dispensing patty separators or squares of paper 44 on the top of theconveyor 42 so that the completed patties 40 may be discharged onto suchpapers 44 from the apparatus 30.

In the apparatus 30 of the present invention the plastic food material38 is fed under pressure from the hopper 36 into a novel moldingmechanism 50 at the forward end of the apparatus 30, the principal partsof which are illustrated separately in FIG. 2.

The molding mechanism 50 has a combination cover plate 52 (FIGS. 2 and6) which forms the top wall or cover of a pressurizable material feedchamber 54 (best illustrated in FIG. 3 wherein the cover plate 52 hasbeen removed to permit viewing of the material feed chamber 54). As canbe seen in FIG. 3, the chamber 54 is located adjacent a side wall ofhopper 36 at the bottom of the hopper and in alignment with a hopperdischarge aperture 56. The chamber is defined by the cover plate 52(FIG. 6), by side wall 58, by side wall 60, by end wall 59, by bottommember 61 (FIG. 10) and by a movable bottom plate 62 which is slidablysupported on bottom member 61 and covers an aperture 63 therein.

The plastic food material, such as ground meat, is moved or conveyedforward from the hopper 36 through aperture 56 by a suitable conveyingmechanism, preferably one capable of pressurizing the material 38 withinthe chamber 54. Specifically, with reference to FIGS. 3 and 5, thebottom plate 62 is adapted to reciprocate longitudinally within thechamber 54 on bottom member 61 and has a plurality of first apertures 64and a second aperture 66. A plurality of driven feed prongs or pins 70are mounted from below the plate 62 and are adapted to project upwardlyand forwardly in an inclined orientation through the apertures 64.Similarly, a feeder bar 72 is adapted to project upwardly throughlaterally elongated aperture 66 in an inclined orientation forwardly ofthe pins 70.

The pins 70 and feeder bar 72 are mounted to a drive plate (notillustrated) which is adapted to reciprocate by a suitable drive means(not illustrated) in a longitudinal direction with respect to the feedchamber 54 and to simultaneously be raised and lowered so that the pins70 and feed bar 72 describe a generally rectangular four motion path.

As best illustrated in FIG. 5, this path is in a cycle of foursuccessive movements. The first movement starts with the pins 70 and bar72 in the raised position as illustrated in solid line in FIG. 5. Thefirst movement is horizontal from left to right to feed the material 38forward. The next movement is downwardly to bring the tops of pins 70and the top of feeder bar 72 below the top surface of the bottom plate62. The third movement is horizontal and rearwardly from right to leftand the last movement is upwardly to project the pins 70 and feeder bar72 through their respective apertures into the food material 38--thebeginning position illustrated in solid line.

The construction and operation details of the feed mechanism, includingthe drive means therefore, are well known to those skilled in the artand are described in great detail in U.S. Pat. No. 3,293,688. Attentionis directed thereto, especially to FIG. 8 of that patent whichillustrates a feeder bar 85 and pins 81, as well as to columns 5, 6 and7 which describe a drive means for such a feeder mechanism.

Any suitable feed mechanism may be used with the apparatus in thepresent invention and the mechanism described above having the pin 70and the feeder bar 72 is merely illustrative of one type that may beused. The specific feeder construction, per se, forms no part of thepresent invention.

In any event, regardless of the specific type of feed mechanism employedby the apparatus of the present invention, the food material 38 is movedforwardly to fill the entire food chamber 54 as illustrated in FIG. 4.The feeding mechanism continues feeding the material until material ispacked tightly within the feed chamber 54 and begins to exert anoutwardly directed pressure on the inside surfaces of the feed chamber54. A novel device is provided for sensing the pressure built-up withinthe feed chamber 54 and for opening the chamber 54 to permit a portionof the food material to fill a novel multiple pressurizingcylinder/piston assembly or molding device mounted above the chamber 54and generally designated by numeral 80 in FIG. 2.

Specifically, side wall 58 of feed chamber 54 has a guide sleeve 82formed therein. A pressure sensing means or piston 84 is slidablydisposed within guide sleeve 82 and has a solid end face 87 (FIG. 11)generally parallel to the side walls 58 and 60. This face 87 is adaptedto be contacted by the food material 38. The pressure sensing piston 84projects outwardly from the guide sleeve 82 and has an end wall 86adapted to engage an upstanding actuating member 88 which is pivotablymounted, as is best illustrated in FIG. 1, on the apparatus base 32 bypin 90 between brackets 92. The feeding pressure within chamber 54 thuscauses the piston 84 to move outwardly with respect to the chamber.

Member 88 is biased inwardly to force the sensing piston 84 inwardly infeed chamber 54 by two springs 94 which are always under tension andwhich are secured between the member 88 and a suitable anchor (notillustrated) within the enclosure 34. Thus, when the chamber 54 is fullof material 38 but not subject to feeding pressure, or when the chamberis empty, the piston 84 is in the inwardmost position as illustrated inFIG. 3.

Mounted to the upper end of member 88 is an L-shaped slidable closureplate 96 which is best illustrated in FIGS. 6, 8 and 11. The closureplate 96 is adapted to reciprocate transversely of the feed chamber 54in a slot 97 in the cover plate 52. Cover plate 52 also has a feedaperture 100 which is closed by closure plate 96 when the closure plateis moved to its inwardmost position (FIG. 11). The aperture 100 is openwhen closure plate 96 is moved to its outwardmost position (FIG. 6).

As can be seen from FIGS. 2 and 6, the feed aperture 100 and closuremember 96 are located below the multi-cylinder molding device 80. Themolding device 80 is mounted directly to a support plate 112 which inturn is supported above cover plate 52 by spacer bars 114 and 115 oneither side of the support plate 112. Mounting plate 112 has a pluralityof plug forming cavities 113 in communication with the mold device 80.

A reciprocating transfer plate 110 is slidably disposed between thecover plate 52 and the support plate 112. The transfer plate 110 has twoopposed, parallel flat surfaces 116 and 117 (FIGS. 9-12) by which theplate 110 is specifically adapted to slide between the cover plate 52and the mounting plate 112. The plate 110 has a transfer cavity or feedpassage, such as aperture 118 through which food material 38 is fedthrough the cavities 113 in plate 112 to the molding device 80 asillustrated in FIGS. 8 and 9. Plate 110 also has an aperture of cavity119 which functions as a mold opening in which a patty of food materialis eventually molded by the molding device 80 in conjunction with theunderlying surfaces of the cover plate 52 and the closed closure member96 as illustrated in FIG. 12 for a patty 121.

The transfer plate 110 is reciprocated between a patty discharge orejecting position (FIGS. 2 and 14) and a patty molding position (FIGS.10, 11 and 12) by any suitable reciprocating drive mechanism of whichthere are many known to those skilled in the art. In the embodimentillustrated, the end of transfer plate 110 is shown mounted to, andguided by, a pair of rods 120 (FIGS. 1 and 2) via brackets 122. As bestillustrated in FIG. 1 for the near side of the apparatus 30, eachbracket 122 is connected to a linkage system, which includes linkmembers 124, 126 and 128. By appropriate movement of link 128 through asuitable cam and gear transmission system (not illustrated, but locatedwithin enclosure 34), the transfer plate 110 can be intermittentlyreciprocated between the patty ejecting position and the moldingposition. Conventional lost-motion linkages may be employed to effectthis intermittent motion. The mechanisms for producing such intermittentreciprocating motion of the transfer plate 110 from a central rotatingdrive shaft or other drive devices are numerous and well known to thoseskilled in the art. Hence, a detailed illustration of such a mechanismand a detailed description of its operation are not necessary here. Thespecific design per se, of the mechanism for effecting the reciprocatingmovement of the transfer plate 110 is not part of the present invention,though the combination of a suitable mechanism with other featuresdescribed herein constitutes a form of the apparatus of the presentinvention and permits an apparatus to effect one form of the method ofthe present invention.

When the transfer plate 110 is in the patty discharge or ejectingposition (FIGS. 2, 8, 9, and 14) the food material 38 is forced from thefeed chamber 54 through the feed aperture 100, through the transfercavity 118 in the transfer plate 110 and then through the support platecavities 113 into the molding device 80. To this end, the molding device80 is mounted to the plate 112 directly above, and in alignment with,the feed chamber aperture 100 and includes a multi-cylinder block 140which contains an array of plug forming bores or cavities 144 which arealigned with the cavities 113 in plate 112. Preferably the plug formingcavities 144 extend completely through the block 140 and each alignedpair of cavities 113 and 144 define a generally elongate prismaticvolume such as a right cylinder. Preferably the cylindrical plug formingcavities 113 and 144 are arranged in a generally uniform array in theblock 140 and plate 112. The plate 112 has a bottom surface 146 definingtherein the bottom open ends of the cavities 113 in a plane normal tothe longitudinal axes of the cylindrical cavities 113.

It is to be noted that the cross-sectional views of the multi-cylinderedmold device 80 and plate 112 shown in FIGS. 8, 9, 10, 11, 12 and 14 aresomewhat simplified in that they illustrate only two or three of theplug forming cavities 113 and 144. It is to be understood that plate 112and block 140 preferably have a large number of plug forming cavities,e.g., 150 or more.

As is best illustrated in FIG. 7, a piston 148 is slidably disposedwithin each plug forming cavity 144 and is adapted to movelongitudinally within each plug forming cavity 144 from a retractedloading position (FIGS. 8, 9, 10 and 11) to an extended plug dischargingposition (FIGS. 12 and 14). To this end, one end of each of the pistons148 is suitably mounted to or held within upper mounting block 150.

With reference to FIGS. 2, 8, 9, 10 and 11, it can be seen that theblock 150 and the pistons 148 mounted thereto are not rigidly fixed toany support structure and therefore "float" with respect to, and above,the lower block 140. As best illustrated in FIGS. 2 and 8, a stop means154 is mounted above the block 150 to limit the upward travel of theblock and to thereby determine the maximum internal volume definedwithin the plug forming cavities between the bottom open ends of thecavities 113 and the pistons 148 therein.

As shown in FIG. 2, the stop means 154 is mounted on a support standcomprising two vertical members 156 and 158, two parallel cross members160 and 162 mounted to the vertical members 156 and 158, and a generallyhorizontal plate 164 secured to bottoms of members 160 and 162. Plate164 has a threaded aperture (not visible in FIG. 2) for receiving thestop means 154. Specifically, stop means 154 comprises a threaded rod168 which is threadingly engaged with the plate 164 through the aperturetherein and has on the lower distal end thereof a nut 170 and threadedstop member 172. The vertical height of the threaded stop member 172above the mold device 80, and hence, above the upper mounting block 150,can be varied by appropriate adjustment of the threaded rod 168.

The upper piston mounting block 150 is urged downwardly to form thepatty in the mold opening 119 of the transfer plate 110, as will beexplained in more detail hereinafter, by a hydraulic actuator means 180.The hydraulic actuator means 180 is mounted through an aperture (notillustrated) in plate 164 above the block 150 and comprises a hydraulicactuating cylinder 182 which is supplied with hydraulic fluid throughhydraulic line 184. A piston rod 186 projects downwardly from cylinder182, with a threaded portion at the distal end of the rod carrying a nut188 and a bearing member 190 which is adapted to bear against the topsurface of the mounting block 150. The bearing member 190 is notconnected to the block 150 but is at all times in surface-to-surfacecontact therewith.

The actuator means 180 is intermittently pressurized through hydraulicline 184 by a hydraulic cylinder 194 (FIG. 12) which has a projectingpiston rod 196 adapted to be engaged by a rotating cam 198. Cam 198 ismounted to a drive shaft 200 which is rotated by a suitable drive meansat a predetermined, but preferably adjustable, frequency. The shaft 200may be driven through a gear transmission system (not illustrated) by amotor which also reciprocates the transfer plate 110 as previouslydiscussed. Alternatively, the shaft 200 may be rotated by a separatemotor and control system if desired.

To prevent the food material 28 from passing upwardly in any annularclearance region between each piston 148 and its pair of alignedcavities 113 and 144, a resilient plug 149 can be secured to the end ofeach piston as illustrated in FIG. 13. When food material is underpressure in the cavities, each plug 149 is compressed in thelongitudinal direction of the cavity so that the diameter of the plugincreases so that the exterior surface of the plug is tightly forcedagainst the wall of the cavity. Typically the plug 149 is fabricatedfrom a thermoplastic material having a relatively low coefficient ofsliding friction so as not to unduly inhibit the reciprocating motion ofthe pistons 148 within the cavities.

A mold patty, such as patty 121 in FIG. 14, may be ejected from the moldopening 119 in the transfer plate 110 by a knock-out device 220 asillustrated in FIGS. 2 and 14. The knock-out device includes a verticalmoveable cup 222 that is reciprocated in a vertical direction as shownby the arrow 223 in FIG. 14 into and out of the mold opening 119 duringa pause in the movement of the transfer plate 110. The knock-out device220, including the cup 222 and apparatus for moving it in a verticaldirection 223 may be of any of those customarily used and widely known.Examples of such knockout or patty removing apparatus are shown anddescribed in U.S. Pat. Nos. .[.2,293,688.]. .Iadd.3,293,688 .Iaddend.and.[.2,417,425.]. .Iadd.3,417,425.Iaddend..

The operation of the apparatus in the disclosed embodiment is believedto be obvious from the above description. However, a brief summary ofthe operation is as follows.

Plastic food material, such as ground meat and the like, is loaded inthe hopper 36 as illustrated in FIG. 1. The material 38 is fed from thehopper 36 into the feed chamber 54 and from there into the mold device80 by the feeder means comprising the pins 70 and bar 72 as is bestillustrated in FIGS. 3 and 4. During this initial feeding andpressurization stage, the transfer plate 110 is in the positionillustrated in FIGS. 8 and 9 with the transfer cavity 118 aligned overthe aperture 100 in cover plate 52.

As pressure builds up within the chamber 54, the pressure sensing piston84 is moved outwardly by the food material 38 as illustrated in FIG. 8.The pressure within the chamber 54 is diagrammatically illustrated inFIG. 8 by the outwardly radiating arrows 260. The piston 84 movesoutwardly against the inwardly biased member 88, overcoming the force ofthe springs 94, so that the closure member 96 is carried with the member88 to the outermost position illustrated in FIG. 8 to open the aperture100 and permit the pressurized food material 38 to flow into thetransfer cavity 118, through the plurality of aligned plug formingcavities 113 in support plate 112, and into plug forming cavities 144 inthe block 140. As this occurs, the pistons 148 within the cavities arepushed upwardly. The upper plate 150 to which the pistons 148 aremounted is thus moved upwardly and forces the hydraulic actuator bearingmember 190 upwardly also. At this point the cam 198 (FIG. 1) is in anorientation which permits piston rod 196 to extend to its outermostposition with respect to its cylinder actuator 194 so that the hydraulicfluid within the cylinder actuator 182 may be discharged from theactuator 182 through the hydraulic line 184 and into the cylinderactuator 194. Thus, cylinder actuator 182 is not pressurized at thispoint and the bearing member 190 is free to move upwardly in response tothe upward force exerted on it by the upwardly moving block 150.

Eventually the food material within the plug forming cavities raises thepistons 148 to a predetermined elevation whereat the block 150 contactsthe stop member 172. Further feeding of material 38 causes a greaterpressurization with the feed chamber 54 and within the plug formingcavities.

Next, the feeding pressure is subsequently reduced and the closuremember 96 moves from the open position to the closed position overaperture 100 as illustrated in FIG. 11. To this end, the stroke of thefeeder mechanism, that is, the forward stroke of the pins 70 and bar 72in the horizontal forward direction with the feed chamber 54 (FIGS. 3, 4and 5), is adjustable and is set to feed a predetermined amount ofmaterial with each forward stroke at a predetermined pressure when theupper block 150 is abutting the stop member 172. When the pins 70 andbar 72 are retracted downwardly through the reciprocating plate 62 (FIG.5), the pressure within the chamber and, hence, within the plug formingcavities, is reduced substantially. With little or no pressure onsensing piston 84, member 88 and plate 96 are then urged inwardly by thesprings 94, as illustrated in FIG. 11, to close aperture 100.

In the next step, the transfer plate 110 moves to the molding positionillustrated in FIG. 10 to align the mold opening 119 under the molddevice 80 after the plug forming cavities 144 have been filled with apredetermined amount of material 38 at a predetermined pressure. Whenthis occurs, the transfer cavity 118 necessarily shifts, to the left inFIG. 10, with a residue supply of food material 39 still eventually tobe forced into the plug forming cavities when the entire cycle isrepeated.

In order to prevent material from being fed from the chamber 54 into theempty mold opening through aperture 100, it is necessary that theclosure member 96 completely close the aperture 100 before the transferplate 110 is moved. To this end, the timing of the reciprocation of thetransfer plate 110 is correlated with the timing of the feeder mechanismin chamber 54 so that the plate 110 is not moved until the feeder pins70 and feeder bar 72 have retracted below the chamber 54 as illustratedin FIG. 10 and the closure member 96 has completely closed off theaperture 100. The timing of the transfer plate reciprocation can beaccomplished directly through conventional linkages, lost motion orotherwise, with the drive mechanism for the feeder pins 70 and bar 72.Alternatively, if the transfer plate were reciprocated by separate drivemechanisms, a suitable position switch and associated control system maybe employed to sense when the closure member 96 has completely closedoff the aperture 100 and to actuate the movement of the transfer plate110 at that point in time.

In any case, when the transfer plate 110 has been moved to the pattymolding position illustrated in FIG. 10, the plugs of food materialwithin the plug forming cavities are next discharged into the moldopening 119. FIG. 12 shows the material formed into a patty 121 in themold opening 119. The timing of cam 198 is set so that the piston rod196 is pushed to its innermost position by cam 198 to pressurize theactuator 182 and cause downward movement of the block 150 and of thepistons 148 mounted thereto. The timing of the cam 198 may beaccomplished through a mechanical system in conjunction with themovement of a transfer plate 110 and the feeder pins 70 and feeder bar72. Alternatively, if the cam 198 is separately driven, the cam drivemay be made directly responsive to the position of the transfer plate110 through a suitable position switch and control circuit.

In any event, downward movement of the pistons 148 within the plugforming cavities causes the discharge or extrusion of a portion of thefood material from each cavity and forces the material against the lowersurface of the mold opening 119 which, in the illustrated embodiment inFIG. 12, is defined by a portion of the top surfaces of the cover member52 and of the closure member 96.

The top surfaces of the cover plate 52 and closure plate 96 function asa mold impingement surface against which the leading ends of the plugsof food material impinge as best illustrated in FIGS. 15 and 16. FIG. 15shows a greatly enlarged view of a portion of the support plate 112 withthe plurality of cavities 113 therein and the plugs of food material 38being forced from the open ends of the cavities against the top surfaceof the cover plate 52. As each plug of food material impinges againstthe top surface of the cover plate 52 and pistons 148 continue to movedownwardly, the diameter of the plug increases so that the plug expandscircumferentially.

As illustrated in FIG. 16, as more and more material is forced into themold opening by the pistons 148, the plugs of material circumferentiallyexpand in directions generally perpendicular to the discharge orextrusion direction so that exterior portions of each plug come intocontact with portions of adjacent plugs and so that the contactingportions are somewhat flattened. As these expanded plugs are formedwithin the mold opening 119, air in the mold opening is trapped withinthe interstitial voids between portions of adjacent plugs.

The extruded and expanded plugs are thus formed in a packed array toform a patty 121 as diagrammatically illustrated in FIG. 17. An enlargedportion of patty 121 is shown in perspective in FIG. 18 wherein theexpanded plugs 300 are shown with exterior portions in contact withother adjacent plugs and with interstitial voids 310 defined betweenother exterior portions of adjacent plugs.

Preferably the pistons 148 are not moved downwardly an amount that wouldcause them to project into the mold opening 119. To this end, the lengthof the pistons 148 is adjusted so that when the upper piston moldingblock 150 moves to its downwardmost position, as illustrated in FIG. 12,the distal ends of the pistons 148 are still located within thecylinders 113 of the support plate 112 so that the distal ends arespaced away from the mold opening 119 and hence away from the moldedpatty 121 therein as clearly illustrated in the enlarged view of FIG.16.

After the patty 121 has been formed, the transfer plate 110 issubsequently reciprocated to the patty ejecting position as illustratedin FIG. 14 so that the patty 121 can be ejected by knock-out device 220downwardly onto the receiving paper 44 on belt conveyor 42.

When the patty 121 is in the ejection position illustrated in FIG. 14,the transfer cavity 118, which is still filled with the residual foodmaterial 39, is necessarily positioned below the mold device 80 andabove the transfer aperture 100.

At this point the feeder mechanism, comprising the feeder pins 70 andbar 72, has been moved rearwardly below the chamber 54 and then up againinto the chamber as illustrated in FIG. 5 to begin a new forward feedingmovement. At this point the sequence can be repeated to form anotherpatty. However, the chamber 54 is now fully filled with material 38 andthe transfer cavity 118 is filled with the residual material 39 which,when the closure plate 96 opens, will be pushed into the plug formingcavities, along with additional material 38 from the chamber, ifnecessary, to completely fill the cavities 144.

It is thus seen that the apparatus of the present invention forms anovel patty in a unique manner. The patty is seen to comprise aplurality of plugs of food material packed together in an array defininginterstitial voids adjacent each plug so that the patty has apredetermined degree of porosity permitting penetration of air with thepatty. This promotes more rapid and uniform cooking of the patty andaids in retention of the cooking juices.

Preferably the patty is formed in the apparatus of the present inventionso that it has a generally disc-like configuration with twospaced-apart, major, parallel, exterior, side surfaces and a peripheralsurface connecting the two major, exterior, side surfaces. Preferably,the patty has a generally right cylindrical shape.

The plugs of food material forming the patty are preferably generallycylindrical in shape though, owing to the flattening of the sides of theplugs, the plugs do not have a perfect or true cylindrical shape. In anycase, however, the shape of the plugs is prismatic and preferably thetop and bottom end surfaces of each plug are generally parallel.

The patty is formed so that air is initially trapped in the interstitialspaces or regions between the expanded plugs of food material. Further,during cooking, some of the gases generated by the cooking process andsome air may flow out of the interstitial regions. On the other hand,exterior, ambient air may flow into or otherwise penetrate theinterstitial regions during storage of the patty and/or during cooking.Such a patty has been found to have an unusual degree of fluffiness orlightness and has been found to cook extremely well with a high degreeof retention of the cooking juices. Owing to the use of a regular arrayof plugs of food material, the cooking of the patty can be effected witha relatively high degree of uniformity across the patty.

Patties of ground beef, made in accordance with the present invention,have been found to exhibit as little as a 6% weight loss during cooking.As an example, 4 ounce patties of the present invention were found tocook rapidly and to have an average weight of about 3.75 ounces aftercooking. In contrast, the conventionally made 4 ounce patties did notcook as quickly and had an average weight of between only 3 and 3.25ounces after cooking under identical cooking conditions.

Many ground food materials, and especially ground meat, containstring-like tissue fibers which, when the food material is formed intopatties, are distributed within the patty. When such material isinitially ground, the tissue fibers are essentially "balled" up, so thattheir string-like nature is not visibly apparent. However, when theground material is moved across stationary contacting surfaces duringformation of the patty, some of the tissue fibers unwind and may becomealigned in the direction of movement of the ground material and/or patty(or in the direction of movement of any surface moving against astationary patty or mass of ground material). This situation isillustrated in FIG. 19 wherein vertical striations 350 arediagrammatically depicted to show the relative direction of movementbetween a patty 460 and a surface that has been in contact with thesurface of the patty during its formation in accordance with prior arttechniques. The tissue fibers in the patty will tend to become orientedin parallel lines and to align, at least in the surface of the patty,along the striation lines 350. When the patty is cooked, the tissuefibers contract during the cooking process and cause a shrinkage of thepatty in the striation direction. The patty does not shrink as much inthe direction perpendicular to the aligned tissue fibers to that theresulting patty, through initially formed with a circular shape, assumesa somewhat oval shape, indicated in broken line 462 in FIG. 19, aftercooking.

In contrast, with the method of the present invention, forces tending tounwind the tissue fibers are minimized so that the tissue fibers aregenerally randomly distributed in one or more of the plugs of materialand are not as readily unraveled into a generally straight lineconfiguration when the patty surface is subject to friction forces inone direction, as when transferring the patty in a mold transfer platefrom one position to another. Since the tissue fibers do not as easilyunravel from random orientation within each plug (or from within a smallnumber of adjacent plugs), the generally random orientation of thetissue fibers in the patty of the present invention is maintained. Thus,when the patty of the present invention is cooked, the shrinkage isgenerally circumferentially uniform so that the patty maintains thegenerally circular shape.

The novel method of forming the patty of the present invention providesa patty which is generally of uniform density across its diameter.Patties formed by some typical prior art apparatus do not have such auniform density, and do not cook uniformly.

A prior art apparatus for forming a patty of plastic food material isdescribed in U.S. Pat. No. 4,043,728 and is diagrammatically illustratedin FIG. 21. A mold plate 400 is provided with a mold opening 410 and ismounted between an upper plate 420 and a lower plate 430. A piston 440is slidably disposed within a cylinder or bore 450 in the upper plate420 and is adapted to be moved downwardly to force food material(previously loaded into the cylinder 450) into the mold opening 410. Thepiston 440 has a diameter that is generally substantially less than thediameter of the completed, molded patty 460. Consequently, the foodmaterial in the patty directly under the piston 440 is pressurized to agreater extent than material at the periphery of the patty.

The final density gradation within such a patty is diagrammaticallyillustrated in FIG. 21 wherein lines 462 represent the boundary of thecylindrical region under the piston which was subjected to the highestpressure and which is therefore of the highest density. Lines 464indicate a constant, but less density, than existing in the regionwithin lines 462. Similarly, lines 466 represent a constant densitywhich is less than at lines 464 and 462. Lines 468 represent a densityeven less than that existing at lines 466. Though the density variationwithin the patty is illustrated by straight lines (forming frustoconicalsurfaces in three dimensions), it is to be understood that the constantdensity lines may be slightly curved, depending on the actual moldingconditions. The lines shown in FIG. 21 merely illustrating, insimplified fashion, the general variation in density throughout thepatty.

FIG. 22 shows the patty 460 illustrated in FIG. 21 in plan view with thehigher density region defined within circle 462 and with the density ofthe patty decreasing radially upwardly therefrom in the direction of thearrows 470. It will be readily appreciated that patties of the typeshown in FIGS. 21 and 22 will cook unevenly, and they also tend toassume a dome shaped configuration after cooking.

With the patty of the present invention, all of the plugs of material inthe array forming the patty are formed by pistons under the same amountof pressure. Hence, the pressure within each plug is identical and thereis little if any pressure difference across the patty as the patty isbeing formed and in the complete patty. Consequently, to the extent thatuniform density promotes a more uniform cooking of the patty, the pattyof the present invention is an improvement over the above-discussedprior art patty.

Although it may be possible to form the plugs of material of the presentinvention by directly extruding material through a die, asdiagrammatically illustrated for a meat grinder extruder head in FIG.23, certain disadvantages may be encountered with this method.Specifically, the material 500 is forced against a die 510 having bores520 therein. Plugs of the material 500 are thus extruded through thebores 520. However, if the material, such as ground meat, containstissue fibers 530, end portions of a single fiber 530 can be forcedthrough different bores 520. The fibers 530, being small and stringy,are not easily cut and tend to plug up the die 510 instead of passingcompletely through the bores 520. Eventually, such a meat grinder diemust be cleaned out and the tissue fibers removed from the forward sideof the die.

In contrast, the novel apparatus of the present invention, according toone form of the novel method of the present invention, both loads anddischarges the plug forming cavities from the same open end asdiagrammatically illustrated in FIG. 24 for a portion of a moldapparatus 80. Specifically, as the material is pushed upwardly in thedirection of arrow 610 to fill the cavities 113 and 144 in the plate 112and block 140, respectively, the tissue fibers 531, 532, 533 and 534 areforced into the cavities. A portion of one fiber 531 may be forced inone cavity and the remaining portion of that fiber may be forced into anadjacent cavity. However, since the plugs of food material aresubsequently discharged downwardly in the direction of arrow 620 by thepistons 148, the tissue fiber 531 that is partially disposed in morethan one cavity is easily expelled with the formed plugs of material.Thus with the apparatus of the present invention, the multi-cylindermold device cannot be easily plugged up by tissue fibers.

It is also seen that since each plug is a somewhat self-contained unithaving its own boundary surfaces (see FIGS. 16, 17 and 18), the fiberswithin a plug, or within a plurality of adjacent plugs, are not easilymoved by frictional forces across the patty from plug to plug into astraight line orientation. Consequently, a patty formed in accordancewith the invention, and by the apparatus of the present invention, canhave a great number of randomly oriented tissue fibers which are lesslikely to be reoriented in a straight line configuration on the surfacesof the patty when the surface of the patty are subjected tounidirectional frictional forces.

The apparatus of the present invention is seen to effect a novel methodfor forming a patty of plastic food material. In a broad sense, themethod involves forming the plastic material into a plurality ofself-contained plugs and assembling the plugs in a packed array to forma patty with interstitial voids between portions of adjacent plugs.Preferably, the method includes forming the plugs as generally rightcylinders and assembling the plugs in a generally disc-like patty.

In one form of the method of the present invention, and as effected bythe apparatus of the present invention, the plugs are formed byextrusion of material into elongate prism shapes in generally parallelalignment in a common extrusion direction. The extruding movement of theleading end of each plug is then arrested at a common plane generallyperpendicular to the extruding direction and each plug is then expandedcircumferentially, perpendicular to the extruding direction, to bringportions of each plug into contact with adjacent plugs while trappingair within interstitial voids or air spaces between other portions ofadjacent plugs which can function as, among other things, reservoirs forthe cooking juices.

Although lower block 140 of the illustrated embodiment is shown asseparate from support plate 112, it is to be realized that block 140 andplate 112 could be formed as an integral or unitary piece. In that casethe plug forming cavities 144 within block 140 and the transfer cavities113 within plug 112 would merge into a single, continuous smooth-wallcavity.

It is to be realized that the size of the plug forming cavities 144 andtransfer cavities 113, though preferably of the same diameter, could beof any size suitable for forming a patty comprising a plurality of plugsof material in a packed array. Similarly, the pistons 148 within thosecylinders may be varied in size and the stroke length of the pistons maybe varied as necessary depending upon the type of material being molded.

The pistons 148 may be made removable from the mounting block 150 foruse in changing the pistons and/or replacing broken or damaged pistonsas may be necessary. The pistons 148 may also be separately actuated sothat a variation in density across the diameter or width of the moldedproduct may be achieved, if desired. The spacing between the plugforming cavities, as well as the array configuration, may be varied asdesired depending upon the type of materials being molded and thedesired characteristics of the molded product.

A second embodiment of the apparatus of the present invention isillustrated in FIGS. 25 through 28. FIG. 25 shows a cross section of themold forming area of the apparatus similar to FIG. 14 for the firstembodiment of the apparatus previously described. In the firstembodiment illustrated in FIG. 14, the mold device 80 includes amulti-cylinder/piston assembly. In contrast, in the second embodiment,the multi-cylinder/piston assembly is replaced by a singlecylinder/piston and grid assembly, or mold device 80'.

Specifically, in FIG. 25, the mold device 80' is seen to include acylinder 610 above the mounting plate 112, a cylinder end cap 620closing the upper end of the cylinder 610, and a piston 630 slidablydisposed within the cylinder 610. The piston 630 has a piston rod 632projecting upwardly and through an aperture 634 in the end cap 620. Thedistal end of the rod 632 is adapted to engage the bearing member 190 ona hydraulic actuating cylinder (not illustrated, but similar to cylinder182 for the first embodiment illustrated in FIG. 14). The piston can beforced downwardly by downward movement of bearing member 190.

A foraminous member, such as a circular grid plate 640 is disposedacross the bottom circular opening of the cylinder 610 and defines anarray of apertures or passages 642 therein. The mounting plate 112 maybe formed with a large cylindrical bore 644 and counterbore 645 forreceiving the grid plate 640. Alternatively, the mounting plate 112could extend entirely across the bottom of the cylinder 610 and could beprovided with an array of apertures identical to apertures 642 so as toeliminate the need for a separate grid plate 640.

As best seen in FIG. 26, the piston 630 has a peripheral flange 636defining a recess under the piston 630 so that some food material isretained under the piston when the piston is moved outwardly against thegrid plate 640. Preferably, annular flange 636 has a depth of between1/4 inch and 5/16 inch relative to the downwardly facing major face ofthe piston.

The rest of the apparatus of this second embodiment is identical to thatdiscussed above for the first embodiment illustrated in FIGS. 1 through14.

The operation of the second embodiment of the apparatus illustrated inFIG. 25 is basically similar to that of the first embodiment discussedabove. The transfer plate 110 is first positioned as shown in FIG. 25with the transfer cavity 118 aligned below the grid plate 640.

During the feeding of the material 38 from the feed chamber 54, thematerial is forced through the transfer cavity 118 of the transfer plate110, through the apertures 642 in the grid plate 640 and into thecylinder 610 beneath the piston 630. The cylinder 610 functions as areceiving means for holding a supply of the food material above the gridplate 640.

As the cylinder 610 is filled with material, the piston 630 is movedupwardly to a predetermined height. The height may be adjustably set byany suitable means, including an adjustable stop means, similar oridentical to stop means 154 illustrated in FIG. 2 for the firstembodiment of the apparatus.

After the cylinder 610 is filled with material, the closure member 96 ismoved to close aperture 100 below the grid plate 640 and the transferplate 110 is moved from the position shown in FIG. 25 to the left (asviewed in FIG. 25) to bring the mold opening 119 into alignment with thegrid plate 640. The orientation of the transfer plate 110 would then besimilar to that illustrated for the first embodiment in FIG. 10.

The piston 630 is next forced downwardly, as by a hydraulic actuator ina manner described above for the first embodiment of the apparatus, toforce the food material back through the grid plate apertures 642. Whenthe piston 630 is moved downwardly in the cylinder 610, it functions asa pressurizing discharge means for moving the material from the cylinder610 through the apertures 642 and into the mold that is defined by themold opening 119 of the transfer plate, by the upper surfaces of thecover plate 52 and closure member 96, and by the grid plate 640.

The material discharged into the mold forms a relatively porous pattyhaving a relatively low density which permits penetration of air withinthe patty for promoting rapid and uniform cooking of the patty and whichaids in retention of the cooking juices.

The foraminous member 640 may be relatively thick or may be relativelythin. If relatively thick, the apertures 642 could each have a generallycylindrical shape for thereby collectively defining an array ofgenerally cylindrical bores similar to the plug forming cavities 144 inthe multi-cylinder block 140 of the first embodiment of the apparatusdescribed above and illustrated in FIGS. 1 through 14.

On the other hand, the foraminous member 640 may be a relatively thingrid plate so that each grid plate aperture 642, if cylindrical inshape, has a diameter greater than its height.

Preferably however, the grid plate 640 has an array of apertures 642with the novel counterbore design best illustrated in FIG. 27 for oneaperture 642. Specifically, each aperture in grid plate 640 comprises acavity or passage having a first cylindrical bore 650 of diameter D₁ anda second cylindrical bore 652 of diameter D₂. The bores 650 and 652 areconcentrically oriented so that their longitudinal axes are coincident.

It can be seen that the first bores 650 each have a first openingadapted to communicate with either the transfer cavity 118 or the moldopening 119 of the transfer plate 110, depending upon the position ofthe transfer plate during the molding cycle. Further, the second bores652 each have a second opening communicating with the cylinder 610.

Preferably the diameter D₁ of the first bore 650 is substantially lessthan the diameter D₂ of the second bore 652. Further, the height L₁ ofthe first bore 650 is preferably substantially less than the thicknessL₂ of the plate 640. As an example, the plate 640 has been fabricatedand used in the apparatus of the present invention to make a pattywherein the thickness L₂ of the plate 640 is 5/16 inch, wherein theheight L₁ of the first bore 650 is 1/32 inch, and wherein the diametersD₁ and D₂ of the first and second bores 650 and 652, respectively, are1/8 inch and 3/16 inch, respectively.

Use of the grid plate 640 (with the novel counterbore constructionillustrated in FIG. 27) in the apparatus of the present inventionprovides a patty of relatively low density which has air spaces orinterstitial voids for trapping air and retaining cooking juices. Thispromotes a more rapid and uniform cooking of the patty. Specifically,with reference to FIG. 28, it can be seen that as the food material 38is forced through the apertures 642 of the grid plate 640 by the piston630, the food material is extruded as long, generally cylindrical plugs660 which tend to curl and ultimately impinge against the top surface ofthe cover plate 52 or closure member 96 (which together form the bottomsuface of the mold).

The long twisting plugs 660 also tend to expand in diameter. It has beenfound that where the first bore 650 has a diameter D₁ of 1/8 inch, theformed plug expands to between about 3/16 inch and 1/4 inch in diameter.The curling and twisting of each plug 660 into a curlicue configurationprovides an increase in interstitial void spaces and aids in theformation of a relatively low density patty that is very porous.

It is to be noted that in the preferred form of the grid plate asillustrated in FIG. 27, the height of each first bore 650 is relativelysmall compared with the thickness of the plate. Thus, there is arelatively small surface area defining the cylindrical wall of each bore650. This reduced surface area is advantageous since the boundary layerfriction is reduced as the material 38 is discharged through the bore650. That is, if the height L₁ of a bore 650 were much greater, sayequivalent to the thickness L₂ of the plate 640, then the plug 660formed in the bore 650 would be subjected to boundary layer frictionforces for a much greater portion of its length. This would tend toalign the tissue fibers within the food material and to form a moredense plug. By reducing the amount of cylindrical wall surface area thatis in contact with the plug 660 as the plug is being formed, it isbelieved that the density of the plug 660 per se is reduced and that thetendency to align tissue fibers within the plug 660 is also reduced.

The novel grid plate structure of the second embodiment of the presentinvention is self-cleaning during operation. With reference to FIG. 24,it is possible that a single tissue fiber may enter more than oneaperture or cavity during the filling of the cylinder 610 and may thus"hang up" on the bottom openings of the cavities or apertures in thegrid plate 640. When the material is subsequently moved out of thecylinder 610 into the mold, any tissue fibers which were stuck on thebottom of the grid plate 640 will be forced into the mold.

Similarly, a single tissue fiber may, as it is moving out of thereceiving chamber within cylinder 610 and through grid plate 640, hangup on the apertures 642 on the upper side of the grid plate 640.However, during the subsequent filling operation (wherein material ispushed upwardly through the apertures 642 of the grid plate 640 to againfill the cylinder 610), the tissue fibers that were caught on the top ofthe grid plate 640 will be dislodged and moved back into the cylinder610. In this manner, the bidirectional movement of material through thegrid plate 640 will dislodge fibers that have been caught on either sideof the grid plate. Thus, the tendency of the grid plate to plug up withtissue fibers is substantially reduced.

Patties have been made with the second embodiment of the apparatus ofthe present invention. A grid plate was used in which the grid plate was5/16 inch thick, in which each first bore had a diameter of 1/8 inch, inwhich each second bore had a diameter of 3/16 inch, and in which eachfirst bore had a length, as measured along its longitudinal axis, of1/32 inch. The 4 ounce patty of ground beef formed with such a gridplate was found to cook rapidly, in approximately 90 to 100 seconds,with very little reduction in weight. Specifically, the weight reductionin a 4 ounce patty was only about 1/4 ounce during cooking.

A patty formed by the second embodiment of the apparatus of the presentinvention is illustrated in FIGS. 29 and 30. The patty 670 is seen tocomprise a plurality of curled and twisted, elongate plugs 660. Each ofthe plugs 660 is curled and twisted in a prismatic volume 680,approximately cylindrical in shape. Each of these prismatic volumes 680contains one curled and twisted plug 660. Each plug is so twisted andcurled that the prismatic volume 680 has a relatively large number ofinterstitial void spaces for entrapping air and which define reservoirsfor retaining the cooking juices. In addition, void spaces are alsonecessarily defined between the boundaries of the adjacent prismaticvolumes 680 for similarly entrapping air and forming reservoirs whichretain cooking juices.

FIG. 31 illustrates a modification of the patty of plastic food materialof the present invention wherein, a portion of a patty 690 isdiagrammatically illustrated in perspective. A major portion of patty690 is identical to the patty 670 previously described and illustratedin FIGS. 29 and 30. However, the modified patty 690 has an additionalstructural feature which includes a layer 692 for somewhat dense foodmaterial on the top surface of the patty.

Specifically, the layer of plastic food material 692 is relatively densecompared to the underlying portion of the patty. The layer 692 is alsorelatively thin compared to the thickness of the patty 690 and extendscompletely over the top of the patty 690, thereby closing off most ofthe interstitial void spaces below the shear layer 692. The layer 692 ispressed against the tops of the many separate quantities or food volumes680 so that it is attached to the underlying patty structure.

A patty 690 can be formed with the layer 692 by the first or secondembodiments of the apparatus of the present invention by providing acertain amount of clearance between the top surface 116 of the moldtransfer plate 110 and the facing bottom surface 146 of the mountingplate 112. With reference to FIG. 25, if the clearance between thetransfer plate 110 and mounting plate 112 is between about 0.01 to about0.012 inch, the plastic food material trapped within this clearanceregion in the mold area will be subject to frictional forces when thetransfer plate 110 is moved from the patty molding position to the pattyejecting position. As the transfer plate 110 is so moved, the plasticfood material in the clearance region is forced against the top surfaceof the formed patty by the undersurface 146 of the superposed mountingplate 112.

Depending upon the specific clearance in the apparatus, the resulting"shear-formed" layer of plastic food material on the top of the patty ispreferably about 1/64 of an inch thick. In a hamburger patty of typicalcommercial size, the shear layer thickness would be a relatively smallfraction of the thickness of the whole patty--between 1/2 and 1/128inch. Of course, greater or lesser shear layer thicknesses can beachieved by providing greater or lesser clearances in the apparatus.

It is preferable to provide a layer 692 that is thick enough to aid inholding the patty 690 together and to reduce the tendency of the pattyto break apart during handling prior to, during, and after cooking.

It is believed that the layer 692 also functions to trap the air andvapors in the interstitial voids below the layer during cooking tothereby promote more rapid and more uniform cooking of the patty and tothereby aid in retention of the cooking juices.

The layer 692 can be formed more positively by providing a grid plate,such as grid plate 640 in FIG. 25, in which the bottom of the grid platefacing the mold opening is recessed upwardly a slight amount compared tothe bottom surface 146 of the mounting plate 112 in which the grid plateis mounted. This will positively insure that a sufficient amount ofplastic food material is deposited on the top portion of the formedpatty to form the shear layer 692 when the transfer plate is moved fromthe patty molding position to the patty discharge position.Alternatively, an annular spacer ring could be secured to the mountingplate bottom surface 146 concentric with, and outwardly of the gridplate 640 to receive the additional food material for forming the shearlayer.

The patty 690 formed with the layer 692 is intended to be cooked on agrill or other heating surface with the layer 692 on the top of thepatty so as to effectively trap the vapors and juices within the pattyduring cooking. With some types of cooking processes and with some typesof food material, it may prove desirable to also provide a shear layer,similar to shear layer 692, on the bottom of the patty. This could bereadily accomplished with the apparatus of the present invention byproviding sufficient clearance between the transfer plate 110 bottomsurface 117, and the top of the support plate 52 and/or by providing aslight convex recess within the mold region in the support plate 52.

Of course, it is to be realized that the layer 692 can be formed on apatty with both the second embodiment of the apparatus illustrated inFIG. 25 and with the first embodiment of the apparatus illustrated inFIGS. 1 through 14. In the case of the first embodiment of the apparatusof the present invention, a shallow, upwardly convex, recess could beprovided in the mounting plate 112 below the multi-cylinder block 140.The resulting shear layer would cover the top of the patty (illustratedin FIGS. 17 and 18 as formed from an array of closely packed plugs).

In certain processes, and/or with certain plastic food materials withwhich a shear layer may not be desirable, adjustment or construction ofthe apparatus to reduce the clearances (i.e., between the transfer plate110 and the lower support plate 52 and upper mounting plate 112) willeliminate the regions in which excess plastic food material can collect.This will have the effect of producing a "knife-like" cutoff of the foodmaterial on both sides of the transfer plate. With such reducedclearances, the shear layer would not be formed at all, or would beformed so very thin that it would not be able to function to hold thepatty together or retain cooking vapors.

A modification of the second embodiment of the apparatus illustrated inFIGS. 25 through 28 is illustrated in FIG. 32 which shows a crosssection of the mold forming area of the apparatus similar to the areashown in FIG. 28 and previously described.

In this modification however, a thin grid plate 640a is provided betweenthe piston 630 and the mold cavity defined above the top surface ofcover plate 52. The plate 640a has an array of passages, apertures, ororifices, such as generally right cylindrical bores 642a. Preferably,the bores 642a are relatively small, about 1/8 inch in diameter, and arespaced relatively far apart in the grid plate 640a--the spacing betweenthe center lines of the adjacent bores 642a being greater than the borediameter.

It can be seen that as food material 38 is forced through the bores 642aof the grid plate 640a by the piston 630, the food material 38 is formedinto long strings 660a and, owing to the relatively small diameter ofthe bores, the material strings 660a move through the aperture bores andinto the mold opening at a relatively high rate of speed. The material38 fills the mold to form a patty, such as the patty 670a illustrated inFIG. 33, which has a relatively low density and which may becharacterized as having a "fluffy" quality. Such a patty has been foundto cook uniformly and very rapidly.

The exact mechanism by which the material strings 660a are formed intothe relatively low density patty is not completely understood at thistime and there is no intent herein to be bound by any theory or anyexplanation. However, with some types of food, and within certainprocess temperature ranges, it appears that relatively small diameterstrings 660a are ejected at such a high rate of speed into the mold thatthe strings 660a break apart, either before or after impinging upon thesurface of plate 52, to form many small fragments 696 with a vast numberof interstitial air spaces between the fragments 696. The relativelylarge spacing between bores 642a apparently aids in creating the largenumber of interstitial air spaces between the food material fragments696 so that the formed patty has a relatively low density and fluffycharacteristics. With other types of food material, and depending on thetemperature range, the thin strings may not necessarily break intofragments. However, the strings do form curliques of material definingthe desired interstitial void spaces.

It is to be understood that the patty 670a formed according to theabove-described modification of the method illustrated in FIG. 32 couldalso be molded with a "shear-formed" layer on the top and/or bottom ofthe patty as is illustrated for layer 692 on the patty 690 in FIG. 31.The techniques and mechanisms for forming such a layer 692 would besubstantially the same as those previously described with respect to thelayer 692 on patty 690.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the true spirit andscope of the novel concept of the invention. It is to be understood thatno limitation with respect to the specific apparatus illustrated hereinis intended or should be inferred. It is, of course, intended to coverby the appended claims all such modifications as fall within the scopeof the claims.

I claim:
 1. A method for forming a patty of plastic food material,including ground meat and the like, which is subject to shrinkage duringcooking, said method comprising the steps of:(a) forming said materialinto a plurality of plugs having generally oppositely extending ends;and (b) assembling said plugs into a closely packed array to define apatty without substantially inwardly compressing each plug laterally andproviding a substantially continuous layer of material disposed acrossand connecting the ends of said plugs on one of the surfaces of saidformed patty to aid in holding the patty together and, when the patty iscooked on a grill with the layer at the top of the patty, to aid inretaining vapors and juices within the patty to thereby promote morerapid cooking.
 2. The method in accordance with claim 1 in which step(a) includes forming said material into a plurality of generally rightcylinders.
 3. A method for forming a patty of plastic food material,such as ground meat and the like, which is subject to shrinkage duringcooking and which contains elongated tissue fibers, said methodcomprising:(a) feeding a quantity of said material under a predeterminedfeed pressure into a plurality of elongate pressurizable cavitiesthrough open ends in each said cavity; (b) terminating said feeding ofsaid material; (c) disposing an impingement plate adjacent and spacedfrom said open ends of said cavities; (d) discharging said food materialfrom said cavities through said cavity open ends in a generally commondischarge direction to form plugs having general transverse leading endsurfaces with said tissue fibers generally randomly distributed withinthe plugs and with said leading end surfaces of said plugs impingingagainst said plate to cause at least a leading segment of at least oneof said plugs to expand circumferentially and contact lateral surfaceportions of adjacent plugs to form the patty; and (e) retaininginterstitial voids between other portions of adjacent plugs forenclosing air and defining reservoirs for the cooking juices.
 4. Themethod in accordance with claim 3 in which said impingement platedefines a continuous solid impingement surface and in which step (d)includes causing the leading ends of said plugs to impinge against saidimpingement surface.
 5. A method for making a patty of plastic foodmaterial, including ground meat and the like, which is subject toshrinkage during cooking and contains elongated tissue fibers, saidmethod comprising:(a) providing a supply of said plastic food material;(b) providing a plurality of pressure cavities with each cavity havingat least one opening at one end and with a pressure transmitting meansspaced from said opening and moving a quantity of said food materialfrom said supply of food material under pressure through the cavityopenings into said cavities and against said pressure transmittingmeans; and (c) applying pressure in said cavities with said pressuretransmitting means to discharge a portion of the food material therefromout of said cavity openings in discrete extrudate masses into a mold toform a patty.
 6. A method for forming a patty of plastic food material,such as ground meat and the like, which is subject to shrinkage duringcooking and which contains tissue fibers, said method comprising:(a)providing a supply of plastic food material; (b) providing (1) a feedchamber adjacent said supply of food material with a feed aperture insaid feed chamber and a closure member movable for opening and closingsaid aperture, (2) a transfer plate adjacent said feed chamber movablerelative to said aperture in said feed chamber and defining a transfercavity and a mold cavity, and (3) a plurality of pressurizing cylindershaving pistons slidably disposed therein, said cylinders being alignedwith said feed aperture; (c) closing said aperture with said closuremember while feeding a quantity of said material under pressure fromsaid supply along said feed chamber; (d) moving said transfer plate toalign said transfer cavity with said feed aperture and said pressurizingcylinders and then moving said closure member to open said aperture toallow said pressurized material to flow through said transfer cavity andinto said pressurizing cylinders; (e) terminating the feeding of saidmaterial; (f) moving said closure member to close said aperture; (g)moving said transfer plate to align said mold cavity with said feedaperture and said pressurizing cylinders; (h) moving said pistons withinsaid pressurizing cylinders to force said material from saidpressurizing cylinders into said mold cavity to form said patty as anarray of plugs of material with each plug having exterior surfaceportions in contact with adjacent plugs while retaining interstitialvoids between other portions of adjacent plugs; and (i) moving saidtransfer plate to a discharge station and ejecting the patty from saidmold cavity.
 7. A method for forming a patty of plastic food material,said material including ground meat and the like, which contains tissuefibers, said method comprising the steps of:(a) providing mold partsdefining a mold cavity having the shape of said patty; (b) providing aforaminous member defining apertures therein adjacent said mold cavity;(c) forcing said food material from one side of said foraminous memberunder pressure through said apertures to the other side of saidforaminous member and into said mold cavity to thereby extrude aplurality of elongate plugs of said material in generally parallelalignment in a common extruding direction with each plug having aleading end; (d) arresting the extruding movement of the leading end ofeach plug at a substantially common plane; (e) while continuing toeffect step (d), expanding said plugs in directions generallyperpendicular to the extruding direction to bring portions of theexterior surfaces of adjacent plugs into contact to form a patty; and(f) penetrating said foraminous member apertures with means fordislodging tissue fibers lodged on the upstream side of said member. 8.The method in accordance with claim 7 in which step (f) includespenetrating said foraminous member apertures with some of said foodmaterial.
 9. A method for forming a patty of plastic food materialcontaining tissue fibers, said material including ground meat and thelike, said method comprising the repeatable sequence of:(a) providing atleast one mold part defining a mold cavity and a member defining aplurality of openings therein adjacent the mold cavity; (b) moving saidmaterial in a first direction at least into said openings; and (c)moving at least a portion of said material in a second, oppositedirection out of said openings into the mold cavity to form said pattywhereby tissue fibers are dislodged from said member by the movement ofsaid material in said second direction.
 10. A method for forming a pattyof plastic food material containing tissue fibers, said materialincluding ground meat and the like, said method comprising therepeatable sequence of:(a) providing a mold and a member defining aplurality of passages therein adjacent the mold; (b) moving saidmaterial in a first direction at least into said passages; (c) moving atleast a portion of said material from said passages in a second,opposite direction out of said passages into the mold to form said pattywhereby the tissue fibers are dislodged from said passages by themovement of said material in said second direction; and (d) forcing someof said food material from said formed patty over the top of said formedpatty to provide a layer of relatively dense food material to aid inholding the patty together and, when said patty is cooked on a grillwith said layer at the top of the patty, to aid in retaining vapors andjuices within the patty to thereby promote more rapid cooking.
 11. Amethod for forming a patty of plastic food material containing tissuefibers, said material including ground meat and the like, said methodcomprising the repeatable sequences of:(a) providing a mold and a memberdefining a plurality of passages therein adjacent the mold, saidpassages extending through said member and each defining first andsecond openings on opposite sides of said member; (b) moving saidmaterial in a first direction into said passages through said passagefirst openings and out of said passages through said passage secondopenings to dislodge tissue fibers from said passage second openings;and (c) moving a quantity of said material in a second, oppositedirection back into said passages through said passage second openingsand out of said passages into the mold to form said patty whereby tissuefibers are dislodged from said passage first openings by the movement ofsaid material in said second direction.
 12. A method for forming a pattyof plastic food material containing tissue fibers, said materialincluding ground meat and the like, said method comprising therepeatable sequence of:(a) providing a mold and a member defining aplurality of passages therein adjacent the mold; (b) moving saidmaterial in a first direction into said passages and through saidpassages into a receiving chamber with some of said material remainingin said passages; and (c) moving at least a portion of said materialfrom said receiving chamber in a second, opposite direction back intosaid passages to discharge said material as a plurality of elongate,curling plugs into the mold to form a patty with interstitial voidswhereby tissue fibers are periodically dislodged from said passages bythe movement of said material in said first and second directions.
 13. Amethod for forming a patty of plastic food material, including groundmeat and the like, which contains tissue fibers, said method comprisingthe steps of:(a) providing parts defining a mold cavity having the shapeof said patty; (b) providing a foraminous member defining aperturestherein adjacent said mold cavity; (c) forcing said food material fromone side of said foraminous member under pressure through said aperturesto the other side of said foraminous member and into said mold cavity asdiscrete extrudate masses with each mass having at least a leading endsegment; (d) continuing to force said food material into said moldcavity to form a patty with the leading end segments of at least some ofsaid masses impinging against a region of said mold cavity parts andbuckling to bring buckled mass portions into overlapping relationship;and (e) penetrating said foraminous member apertures from said otherside of said foraminous member with aperture entering means fordislodging tissue fibers lodged on the upstream side of said member. 14.The method in accordance with claim 13 in which step (d) also includesbreaking at least a portion of some of said discrete masses intofragments.
 15. The method in accordance with claim 13 in which step (e)includes penetrating said foraminous apertures with some of said foodmaterial. .Iadd.
 16. A process for making a patty of plastic foodmaterial containing tissue fibers by the steps of forcing said plasticfood material from a bulk supply of said food material into a moldcavity under pressure and then removing the formed patty from the moldcavity, said method characterized by the following steps:(a) providing aforaminous member having an array of apertures for use in said process;(b) forcing said food material from said bulk supply under pressure to alocation adjacent said foraminous member; (c) providing mold parts todefine said mold cavity and disposing said mold parts directly adjacentsaid foraminous member with a mold opening at the interface of saidforaminous member and said mold cavity for permitting passage of saidfood material from said foraminous member directly into said mold cavityin the absence of mixing instrumentalities at said interface; (d)forcing said food material at least into said foraminous memberapertures and then out of said apertures as discrete extrudate massesinto said mold cavity with at least some of said extrudate masses beingforced against said mold parts of said mold cavity until said moldcavity is substantially filled with said extrudate masses to form saidpatty completely surrounded by said mold parts except for said moldopening adjacent said foraminous member; (e) before, during, or afterstep (d), effecting multidirectional movement of said food material atthe apertures in said foraminous member to prevent clogging of saidapertures with tissue fibers; (f) moving said mold parts together and/orrelative to each other to permit access to said formed patty; and (g)removing said formed patty from said moved mold parts. .Iaddend..Iadd.17. The process in accordance with claim 16 further characterizedin that step (b) includes feeding said food material through saidapertures which are each defined by a generally cylindrical bore..Iaddend. .Iadd.18. The process in accordance with claim 16 furthercharacterized in that step (d) is effected to form long, twisting plugsof said extrudate masses. .Iaddend. .Iadd.19. The process in accordancewith claim 16 further characterized in thatstep (d) includes forcingsaid food material out of said foraminous member apertures as extrudatemasses which expand in diameter. .Iaddend. .Iadd.20. The process inaccordance with claim 16 further characterized in that step (c) includesthe step of providing said mold parts in the form of a cover plate and amold plate movable adjacent said cover plate between a patty moldingposition and a patty discharge position; said mold plate being providedwith said mold cavity that is defined in part, when said mold plate isin said patty molding position, by said cover plate at one side of saidmold plate and that presents said mold opening at the other side of saidmold plate for accommodating passage of said food material; said step ofproviding said mold plate also including the step of disposing said moldplate adjacent said foraminous member to locate said mold opening at theinterface of said foraminous member and said mold cavity with said moldplate in said patty molding position and step (d) includes forcing atleast some of said extrudate masses in said mold cavity against saidcover plate. .Iaddend. .Iadd.21. A process for making a patty of plasticfood material containing tissue fibers by the steps of forcing saidplastic food material from a bulk supply of said food material into amold cavity under pressure and then removing the formed patty from themold cavity, said method characterized by the following steps: (a)providing a foraminous member having an array of apertures for use insaid process; (b) forcing said food material from said bulk supply underpressure to a location adjacent said foraminous member; (c) providingmold parts to define said mold cavity and disposing said mold partsadjacent said foraminous member with a mold opening at the interface ofsaid foraminous member and said mold cavity for permitting passage ofsaid food material from said foraminous member into said mold cavity;this step (c) of providing mold parts including the step of providingsaid mold parts in the form of a cover plate and a mold plate movableadjacent said cover plate between a patty molding position and a pattydischarge position; said mold plate being provided with said mold cavitythat is defined in part, when said mold plate is in said patty moldingposition, by said cover plate at one side of said mold plate and thatpresents said mold opening at the other side of said mold plate foraccommodating passage of said food material; said step of providing saidmold plate also including the step of disposing said mold plate adjacentsaid foraminous member to locate said mold opening at the interface ofsaid foraminous member and said mold cavity with said mold plate in saidpatty molding position; this step (c) of providing mold parts alsoincluding the step of positioning said cover plate member and saidadjacent, movable mole plate at a distance spaced apart sufficient toprovide a clearance of greater than about 0.01 inch; (d) forcing saidfood material at least into said foraminous member apertures and thenout of said apertures as discrete extrudate masses into said mold cavitywith at least some of said extrudate masses being forced against saidmold plate of said mold cavity until said mold cavity is substantiallyfilled with said extrudate masses to form said patty completelysurrounded by said mold parts except for said mold opening adjacent saidforaminous member; (e) before, during, or after step (d), effectingmultidirectional movement of said food material at the apertures in saidforaminous member to prevent clogging of said apertures with tissuefibers; (f) moving said mold parts together and/or relative to eachother to permit access to said formed patty, this step (f) including thestep of moving said mold plate to said patty discharge position whereby,during said movement of said mold plate, the food material trappedwithin said clearance is subjected to frictional forces to form a layerof food material on one side of said patty, which layer aids inretaining vapors and juices when the patty is cooked on a grill with thelayer at the top of the patty; and (g) removing said formed patty fromsaid moved mold parts. .Iaddend. .Iadd.22. The process in accordancewith claim 16 further characterized in that step (d) includes forcingsaid food material out of said apertures as discrete extrudate masseswhich each have the form of an elongate, curling plug of material with agenerally circular transverse cross-section. .Iaddend.